Double glazing unit



Aug. 2, 1938. J. H. FOX

DOUBLE GLAZING UNIT Filed June 25, 1936 IN V EN TOR. (/OH/Vfi F'o/ Y B 4 TORNEYS.

Patented Aug. 2, 1938 PATENT OFFICE 2,125,312 DOUBLE GLAZING UNIT John H. Fox, Pittsburgh, Pa., aaslgnor term-- burgh Plate Glass Company, a corporation of Pennsylvania Application June 23, 1936, Serial No. 86,787

The invention relates'to double glazing units which consist of a pair of glass sheets in parallel with spacing and sealing means between the sheets at their edges. It is customary" to supply 5 the insulating space between the sheets with dehydratedair or other gas, such as nitrogen, in order to prevent condensation on the inner faces of the sheets due to temperature changes. The maintenance of the gas in dry condition presents one of the main problems in connection with double glazed units, since leakage of moistureladen "air through and past the spacing members, in the course of time, is practically inevitable, so that provision is made in many installa- 15 tions for the connection of dehydrating apparatus to the insulating space to permit a renewal of the drygas when the glass begins to cloud.

Heretofore, the connections for accomplishing this result have been made by the use of tubes extending through the spacers. This requires either a special sash construction through which the tubes lead, or the removal of the unit from the sash to gain access to the ends'of the tubes, and both methods are open to objection from the standpoint of cost. The present invention is designed to overcome this objection and provide a unit which leaves the spacers intact and permits dehydration without removing the unit from the sash and without the necessity of perforating 3 the sash and installing conduits therethrough. Briefly stated, the desired result is secured by perforating one of the glass sheets and installing in such perforations outlet plugs provided with closures which may be removed when it is desired 35 to connect the tubing of a dehydrating apparatus to the space between the sheets. These plugs can be made relatively small and capped, so that they do not detract noticeably from the appearance of the unit. One'embodiment of the inven- 40 tion is shown in the accompanying drawing,

wherein:

Figure 1 is a front elevation of the unit, and Fig.2 is an enlarged section through the unit on the line lIII of Fig. 1.

45 Referring to the drawing, 3 and l are the glass sheets; 5 is the spacer which may be of rubber or any other suitable material sealing the edges of the insulating space 6 between the sheets; and

I is a U-shaped metal frame, which in some cases 50 may be omitted. I

The glass' sheet 3 is perforated at two points,-

preferably near the upper edge of the sheet and by the use of a sand blast, and the plugs 8 are fitted in the perforations, as indicated in Fig. 2. 55 The plug in each case consists of the flanged 3 Claims. '(oi. 20-565) sleeves 9 and I0 threaded together with packing washers ii and I! of rubber, or the like, beneath the flanges. A metal washer i3 is preferably used between the packing washer H and the flange of the sleeve 9. This washer I3 is of such 5 diameter that its edge projects out past the periphery of the flange of the sleeve 9, as shown, the purpose being to provide a ledge for holding the-cap i4 releasably in position. The edge of the cap is turned in slightly, as shown, so that 10 when the cap is pressed into position, its edge will snap beneath the edge of the washer i3, thus holding the cap securely, but releasably in position. I

The sleeve 9 is threaded internally with a conical seat at the end of the threaded portion against which the end of the closure screw I5 engages sealing the passage;

When it is necessary to supply the space 6 with a dry gas, the caps I4 and screws ii are removed,

and the ends of the tubes of the apparatus for supplying dry gas are threaded into the sleeves. After the; necessary circulation of dry gas through the insulating space has been completed and the tubes removed, the screw l5 and cap I are replaced. The plug is necessarily applied to the sheet 3 before the unit is assembled, some clearance being provided between the, sleeve l0 and the wall of the perforation to avoid any danger of cracking the glass either in applying the device or due to temperature changes.

' What I claim is:

1. A fitting for a glass sheet having a perforation therethrough comprising, a metal connection plug having a threaded passage therethrough fitting said perforation in sealing relation with the glass sheet, a removable closure member threaded into said passage, and a cap fitting over the outer end of said connection and having releasable snap engagement therewith. 40

2. A fitting for a glass sheet having a perforation therethrough comprising, a metal connection plug having a passage therethrough fitting said perforation in sealing relation with the glass sheet and'comprising a pair of flanged sleeves threaded together in said perforation with the flange on one sleeve lying in opposition to the outer face of the glass sheet and the flange on the other sleeve lying in opposition to the inner face of the glass sheet, a removable closure memher threaded into said passage, and a sheet metal cap fitting removably over the flange of the sleeve lying on the outer side of the glass sheet.

3. A fitting for a glass sheet having a perforationtherethrough comprising, a metal connection plug having a passage therethrough fitting said perforation in sealing relation with the glass 'sheet and comprising a pair of flanged sleeves threaded together in said perforation with the flange on one sleeve lying in opposition to the outer face of the. glass sheet and the flange on the other sleeve lying in opposition to the inner face of the glass sheet, a removable closure memthe glass, and a cap fitting over the outer end of the sleeve and having a. snap engagement with the washer.

- JOHN H. FOX. 

